纳米线织构的多晶硅太阳电池研究

STUDY OF NANOWIRES TEXTURED POLYCRYSTALLINE Si SOLAR CELL

采用无电化学刻蚀技术，通过优化AgNO，浓度、刻蚀温度和刻蚀时间，研究在125mm×125mm多晶硅片表面制备均匀分布硅纳米线阵列的方法，获得了硅纳米线织构的多晶硅在宽光谱范围内（300～1000nm）平均反射率约为8％。成功制备了表面具有硅纳米线织构的多晶硅太阳电池，并通过两种改进方法提高太阳电池效率：1）优化硅纳米线阵列的长度（约1.5μm），并利用PECVD方法在硅纳米线阵列表面生长70nmSi3N4薄膜进行表面钝化，纳米线织构的多晶硅太阳电池效率从8．95％提高到了11．41％。2）使用HNO，和HF混合溶液去除硅衬底背表面的硅纳米线阵列，使铝背电极与多晶硅紧密接触，太阳电池效率进一步提高到13．99％。研究表明：所采用的改进方法能有效提高纳米线织构多晶硅太阳电池的效率。

In this paper, electroless chemical etching method is used to prepare uniformly Si nanowire arrays （SiNWs） in 125 mm×125 mm polycrystalline Si wafer, through optimizing the concentration of AgNO3, etching temperature and etching time. The reflection of the SiNWs is about 8 % in the spectrum ranging from 300 nm to 1000 nm. We fabricated successfully the SiNWs textured polycrystalline Si solar cell and increases the efficiency by using two improved methods ： 1） optimizing the length of SiNWs （1.5 μm） , and growing 70 nm Si3N4 on the surface of SiNWs with PECVD, the efficiency increases from 8.95% to 11.41%. 2） Removing the SiNWs on the back surface of wafer with HNO3 and HF mixed solution to obtain closely contact between A1 electrode and wafer, the efficiency enhances further to 13.99%. The results demonstrated that the improved methods can increase the efficiency of SiNWs textured polycrystalline Si solar cell effectively.